1. Field of the Invention
The present invention relates to a radar antenna system, and more particularly, to a radar antenna system capable of selectively operating in one of the amplitude-comparison mono-pulse mode and the phase-comparison mono-pulse mode.
2. Description of the Prior Art
Radar has been widely used in military equipment and terrain exploration, and also used in detecting positions of different objects. An operational principle of radar is to transmit electromagnetic signal to the air and receive the reflected signal from an object, so as to calculate a direction, a range and a speed of the object. As radar technology evolves, the mono-pulse technology is widely used in the radar related area. Compared to traditional radar, the mono-pulse radar may obtain the direction and the range of the object by simply transmitting a mono-pulse signal. The mono-pulse radar has become one of the most popular radar recently.
Specifically, the mono-pulse radar detects a position of the object by receiving and analyzing the reflected signal received by the antenna. The mono-pulse radar having a fine angular resolution would be limited by a narrow angular scanning scope. On the other hand, the mono-pulse radar having a wide angular scanning scope would be suffered by a coarse angular resolution. Therefore, how to provide a radar antenna system having both fine angular resolution and wide angular scanning scope is a significant objective in the field.